The purpose of treatment for sarcoidosis patients is to improve their quality of life (QoL). In sarcoidosis, measures such as the King’s Sarcoidosis Questionnaire (KSQ) and the Patient Global Assessment (PGA) have been utilized. Researchers used to anchor and distribution techniques to determine the MCID of KSQ general health (KSQ GH), KSQ lung, and PGA, utilizing the least clinically important difference (MCID) as the clinically meaningful change within-patient patient criteria. They examined the discriminatory features of these MCIDs compared to other QoL measures. Patients with sarcoidosis were recruited from six US institutions and evaluated prospectively. Patients completed the St. George’s Respiratory Questionnaire (SGRQ), Short Form 36 (SF-36), Fatigue Assessment Scale (FAS), Sarcoidosis Assessment Tool (SAT), KSQ, and PGA, as well as spirometry, at the start and 6 months. The MCID for improvement or worsening was determined using receiver operator characteristic curves for the anchor approach. For KSQ GH, KSQ lung, and PGA, they used a distribution approach employing half of the standard deviation.

They completed a 6-month evaluation by 271 of the 325 individuals recruited in the research. Based on previously published MCID values on the SGRQ, SF-36, and FAS, nearly half of the patients were worse at 6 months, and 30% were better. There were no situations that contradicted each other. Most of the measures tested have substantial relationships with the KSQ GH, KSQ lung, and PGA. The SGRQ, SF-36, and FAS, all established MCID values, had the best associations. They discovered that most SGRQ and SF-36 domains could determine substantial MCIDs for all three variables using anchor analysis. These MCIDs matched those obtained using the half least square method. Because these values captured >90% of the parameters studied, they propose an MCID of 8 for the KSQ GH, an MCID of 4 for the KSQ lung, and an MCID of 2 for the PGA. Changes in other QoL instruments were distinguished by these MCID values. The calculation of MCID values for KSQ lung, KSQ GH, and PGA could benefit clinical practice and clinical trials.